Nutritional Optimization in Anemic Patients Scheduled for Elective Open-Heart Surgery (Prehab_Nutri)

Operational Definitions Prehabilitation Prehabilitation is personalized, multimodal and individually-tailored intervention that exclusively meets the patient's requirement targeted to improve physiological and metabolic psychological resilience needed before a major stressful event i.e. the surgery in this case.

Solo Nutritional Prehabilitation It is a dedicated nutrition prehabilitation program which works on identifying the patients' nutritional status and identifying malnutrition preoperatively. It is the early beginning of carefully planned and individually tailor made medical nutrition therapy (MNT) Nutrition Screening This is one of the first step which is done when patient is admitted in the hospital. The purpose is to identify patients who are either at risk of malnutrition or those who are already malnourished and in case of diagnosing malnutrition, intervention can be done quickly.

Nutrition Assessment Nutrition assessment means gathering and evaluating pertinent clinical, physical and nutritional data which includes diet, surgical & medical history, medications and psycho-social factors to identify nutritional problems. In the context of malnutrition, the nutrition assessment aids in recognizing patients who are malnourished and nutritional intervention is indicated.

Frailty Frailty is a syndrome which is identified by increased vulnerability, less resistance, reduced physiological reserve, weakness, low gait speed, fatigue, poor mobility, unintentional weight loss and limited ability to maintain homeostasis after stressful events such as the cardiac surgery, that results in high probability of poor clinical outcomes and mortality.

Immune Modulating Formulas These formulas have specific nutrients that modulate the immune system or stimulate the immune response to achieve optimization of nutritional support is promising adjunctive therapy in the section of perioperative care. They contain arginine, glutamine, omega-3 fatty acids, antioxidants, taurine, vitamins and trace elements, such as zinc and selenium. High protein content of the supplements and agents which have Eicosapentaenoic acid (EPA) & Docosahexaenoic Acid (DHA) are known to enhance the immune system both preoperatively and postoperatively. Immuno-nutrition can be found only in enteral formulas Iron deficiency Anemia (IDF) The World Health Organization (WHO) and The National Institute for Health and Care Excellence (NICE) define anemia when hemoglobin levels drop to 13g/L in men over 15 years of age and below 12g/L in non-pregnant women over 15 years of age RESEARCH METHODOLOGY Sample Size Given the primary outcome of the incidence of transfusion in intra-op and post-op period among cardiac patients undergoing elective CABG and Valvular surgeries receiving iron correction therapy; recent cardiac surgery and pre and post-operative blood management literature suggests that the baseline transfusion rates usually range between 30 to 60%.However, with optimizations such as iron correction therapy among others, a reduction of about 20 to 40% is expected. Given that, using G*Power, the sample size was calculated for comparison of two independent proportions. Based on contemporary evidence on perioperative blood management, a transfusion incidence of 50% in the control group and 25% in the intervention group was assumed. With a two-sided alpha of 0.05 and power of 80%, the required sample size was 64 patients per group. After accounting for a 10% attrition rate, a total of 140 patients (70 per group) will be recruited accordingly.

Sampling Technique A consecutive sampling technique will be employed for participants' recruitment.

Consecutive sampling involves the inclusion of every eligible subject over a defined period and is considered superior to convenience sampling in minimizing selection bias. This approach is particularly appropriate in hospital-based randomized controlled trials, where true probability sampling is often impractical. By ensuring that no eligible patients are selectively excluded, consecutive sampling helps reduce selection bias, which can otherwise compromise study validity. In this way, all eligible adult patients undergoing elective CABG and Valvular surgeries at NICVD who meet the inclusion criteria will be approached and enrolled sequentially until the required sample size is achieved. Following the recruitment, the participants shall be randomly allocated to intervention and control groups, ensuring internal validity through randomization. Following recruitment, participants will be randomly allocated to the intervention and control groups upon presentation to the OPD. Patients will be assigned in the treatment and controlled group in 1:1 ratio using block randomization approach with a block size of 10. Randomization sequence will be developed using sealed envelope. Randomization will be implemented using Red Cap randomization module.

Study Setting We have chosen NICVD Cardiac Hospital as part of a purposive sampling technique, as it will represent true cardiac patients benefiting from prehabilitation in the post-cardiac surgery setting.

Sample Selection Patients will be recruited into the study after obtaining written informed consent from those who agree to participate. Eligible participants will include patients whose clinical condition permits a dedicated 8-12-week preoperative period prior to routine elective cardiac surgery, allowing sufficient time to undergo the planned prehabilitation intervention. Patients requiring urgent or emergency surgical intervention will be excluded.

Data Collection Procedure Phase 1 The patients will be recruited through Cardiac OPD. Based on the eligibility criteria, patients will be enrolled in SNP (intervention) group and controlled group (Double arm Trial) The SNP group will undergo the following protocols right after being recruited in the study.

Nutrition Screening Currently there is no validated screening tool which is used exclusive for cardiac surgery patients. In this study we will assess two screening tools for cardiac surgery patients namely; Malnutrition Screening Tool (MST). that comprises of three questions, each question carries a score. At the end, the scores will be added to know the risk of malnutrition. The second tool will be Mini Nutrition Assessment-Short form (MNA-SF). It is generally used for older adults more than 65 years and consists of six questions and scoring will be done at the end to know the status of malnutrition.

Nutritional Assessment Patients will be assessed at baseline using a validated nutritional assessment tool called "Academy/American society for Enteral and Parenteral Nutrition (ASPEN) Malnutrition Consensus Characteristics". The tool entails six questions/ clinical characteristics. It is based on the principle that there's no single indicator of malnutrition and it's imperative to evaluate all 6 clinical characteristics. If any two of these characteristics are found in the patient, the patient is declared as malnourished.This tool is simple to administer and easy to implement, requiring minimal time, and therefore allows for efficient nutritional assessment of patients, even by physicians.

Frailty Assessment Presently, many frailty assessment tools have been developed but which works best for Pakistani admitted for cardiac open heart surgery is not known.

"Clinical Rockwood Frailty Scale (CFS)" is now used extensively in clinical care and in research. It comprises of a nine-point scale to assess a person's level of frailty.CFS has been validated for older people (>65 years) but not in younger population. However, our study will explore both domains.

Frailty will be assessed across all age groups during data analysis using SPSS software. Patients will be stratified into predefined age categories to determine the distribution of frailty across different age groups. Additionally, gender-based differences in frailty will be analyzed to identify which gender demonstrates a higher prevalence of frailty.Two separate brochures will be developed covering all the basic guidelines for cardiac patient. One brochure will provide information on iron-rich diet before cardiac surgery. The second one will cover all the basic dietary guidelines for patients with heart diseases prior and post-surgery. These brochures will be published within the hospital. These brochures will be translated into English and our local language Urdu also. Information on these brochures will be evidence-based and debunk food myths that are commonly followed by both patients and clinicians, during pre and post operative. Moreover, individualized diet plan will supplement patient's requirement.

In addition to this, the SNP group will also be provided with iron correction therapy in the form of oral iron supplements to be used at home for 8-12 weeks.

For the next 8 weeks after the initial visit, the patients will be contacted weekly for follow-ups, either in person or digitally (if they are unable to come in person), to monitor adherence and compliance with the plan.

Compliance with the prescribed nutritional plan will be assessed using a 24 hour dietary recall method, conducted by the principal researcher or trained dietitians.

On 9th week, the patients will be called for follow-up at the clinic and provided with IMF and protein supplements.

Surgery will then take place in the tenth week; after the surgery, the patients will be given IMF & whey protein supplements again along with micronutrient supplements to support wound healing. These will be taken by the patients for two weeks and four weeks respectively.

Micronutrient supplementation in the form of Multivitamin mix of vitamin A, C, E, K, D and zinc, selenium, iron, B complex vitamins and magnesium will be given post operatively for a month to support wound healing.

This will be further aided by high protein diet (to be provided within the hospital) and a comprehensive discharge consultation. These patients will then be monitored for the next four weeks to assess post-surgical outcomes.

Data Collection Data collection will be conducted by trained dietitians and the principal investigator (PI). Dietitians involved in data collection will receive standardized training from the researcher to ensure consistency.

Data collection will be conducted by trained dietitians and the principal investigator. Dietitians involved in data collection will receive standardized training from the researcher to ensure consistency.

Outcome Variables Outcome variables will be evaluated during the intraoperative and postoperative periods to assess the impact of prehabilitation and compare the outcomes with those of the placebo-controlled group.

Statistical Analysis If our data is normally distributed, we will analayze by using Logistic regression and odds ratios. Logistic regression and odds ratios are also robust with non-normal data. However, for comparisons between groups if the data turns out to be non-normal then you can switch towards non-parametric alternatives such as Mann-Whitney U test, Kruskal-Wallis Test, Wilcoxon Rank test Pilot Testing A pilot study will be conducted in an initial cohort of 10 patients to assess the feasibility and potential success of the main trial. This preliminary phase will evaluate process-related feasibility, including recruitment strategies, adherence to the study protocol, and overall workflow efficiency. Operational aspects will also be examined, such as potential challenges in data entry, staffing capacity, and the identification of any procedural limitations that may affect the implementation of the full-scale study.

Adverse effects associated with iron therapy will be closely monitored during the pilot phase. Potential side effects may include constipation, metallic taste, black stools, abdominal pain, nausea, and diarrhea, although these are not expected to occur in all patients. In instances where patients report such symptoms, appropriate management strategies will be implemented, including modification of the supplement type or adjustment of dosing schedules. Patients will be guided accordingly to ensure safety and continued adherence to the intervention.

Standard Perioperative Care In contrast, Participants in the control group will receive standard perioperative care, consisting of preoperative physiotherapy sessions followed by the provision of a nutritional brochure after surgery. Standard physiotherapy care will be identical for both the intervention and control groups.